1. Field of the Invention
The present invention relates to a toner. In a preferred embodiment a toner is described comprising a colorant, a binder resin and a laminar inorganic mineral in which part or all of the ions present between layers are modified by organic ions. The toner can be prepared by a method including dispersing or emulsifying a toner constituent mixture liquid comprising the colorant, the binder resin and/or a precursor thereof, and the laminar inorganic mineral, in an aqueous medium. The density of the laminar inorganic mineral measured by XPS for the toner surface before (A) and after (B) mixing and kneading satisfies the following relationship: A>B.
2. Discussion of the Background
Various kinds of charge control agents are added to control the charging amount of toners. The toner manufactured by a pulverization method, in which a colorant and optional additives are added to a thermoplastic resin functioning as a binder resin and the mixture is pulverized and classified, has the following characteristics: (1) a limitation on size reduction of a toner, meaning that the quality of images is difficult to improve; (2) easy to uniformly disperse the material in each particle but difficult to control the position of the materials therein; and (3) an adverse impact on anti-filming property and fixing property when the amount of a charging controlling agent is increased to improve the charging property of a toner.
Recently, as in published unexamined Japanese patent applications Nos. 2003-515795, 2006-500605, 2006-53313 and 2003-202708, modified laminar inorganic minerals, in which ions existing between the layers are partly modified by organic ions, have been used as a charge controlling agent. These still involve with the characteristics mentioned above.